[cfe-dev] thread(F&&) fails when F is not MoveAssignable

[Gordon Henriksen]

On 2012-12-16, at 15:49, Gordon Henriksen wrote:

> On 2012-12-16, at 15:36, Howard Hinnant wrote:
> 
>> let's zero in on a precise copy/pasteable test.
> 
> Agreed. I'm attempting to reduce a test case.

Found it; the correct reduction has one additional line:

    #define decltype __typeof // CULPRIT

#ifdefing out that 'help' for clang permits the test to work without modification.

Reduction is below.

— Gordon


cat <<'EOT' >test.cpp
#define decltype __typeof // CULPRIT
#include <thread>
#include <iostream>
#include <cassert>

namespace {
   class SimpleJoinThread {
       bool &flag_;
   public:
       SimpleJoinThread(bool &flag) : flag_(flag) { }
       void operator()() { flag_ = true; }
   };
} // End anonymous namespace.

int main()
{
   bool flag = false;
   std::thread(SimpleJoinThread(flag)).join();
   assert(flag);
}
EOT

xcrun clang++ -std=c++0x -stdlib=libc++ test.cpp
./test